CN101218819A - Method and device for synchronizing data service and video service in digital multimedia broadcasting - Google Patents

Abstract

A method and apparatus are provided for transmitting metadata synchronized with audio/video (AV) data over a satellite, terrestrial, cable or proprietary digital broadcast network. The method comprises the steps of: a) receiving an AV time stamp of the AV data; b) calculating a time stamp of the data based on said AV time stamp, said time stamp being information about a point in time at which said data is presented in a user terminal, which Hereinafter, it will be simply referred to as a data timestamp; c) generating synchronization metadata including the calculated data timestamp; and d) encoding the synchronization metadata, and transmitting the encoded synchronization metadata.

Description

Method and device for synchronizing data service and video service in digital multimedia broadcasting

technical field

The present invention relates to Digital Multimedia Broadcasting (DMB); in particular, the present invention relates to a method and apparatus for synchronizing data transmitted based on Eureka-147 with the Or audio and video (AV) data sent later in MPEG-2.

Background technique

The synchronous data service model provides a mechanism for applications running in terrestrial digital multimedia broadcasting (DMB) middleware to execute synchronously with other media, such as DMB video services. Here, the video service refers to the audio/video (AV) service provided based on "Digital Audio Broadcasting (DAB); DMB Video Service; User Application Specification" (ETSI TS 102 428).

FIG. 1 is an exemplary block diagram illustrating a conventional terrestrial DMB transmission system. When the AV signal source 100 generates video and audio signals of DMB, the DMB AV encoder 110 encodes the audio and video signals based on the DMB video transmission and reception interface standard to thereby create an AV stream. This process includes the MPEG-4 AV encoding process and the process of multiplexing into the MPEG-2 Transport Stream (TS). Meanwhile, in order to provide a data service based on Eureka-147, the data signal source 130 generates various data not related to AV data, and the data encoder 140 encodes the various data generated in the data signal source 140 to create a data packet.

The AV stream and data packets output from the DMB AV encoder 110 and the data encoder 140 are multiplexed in the frame (ie ETI frame) of the total transmission interface (Ensemble Transport Interface, ETI) in the total multiplexer 150. The ETI frame undergoes Coded Orthogonal Frequency Division Multiplexing (COFDM) encoding in the DMB transmitter 160 to be output in the form of a Radio Frequency (RF) signal.

Here, the ETI frame mainly includes Fast Information Channel (FIC) data and Main Service Channel (MSC) data. FIC data and MSC data are generated in the FIC unit 151 and the MSC unit 152 of the overall multiplexer 150, respectively.

FIC is an information channel for quick access to multiplexing information and service information in the Eureka-147 system, while MSC is a channel for multiplexing service components. According to the multiplexing structure established through the FIC, each service component corresponds to a service.

Basic audio data, AV streams, and various additional data are multiplexed and transmitted through the MSC. In FIC, absolute time is added to FIG-type 0 extension 10 (FIG 0/10) in the form of Universal Coordinated Time (UCT), and this provides the reference time based on which MSC is decoded and rendered data. Therefore, when encoding data, it is possible to add UCT absolute time information as a criterion for timing information.

MPEG-4 and/or MPEG-2 systems use clock references and time stamps to synchronize AV data sent on the primary stream (ES), and to send timing information.

In the MPEG-4 system, the receiving terminal uses the decoding time stamp (DTS) to define the decoding time point of each access unit in the decoding buffer, and uses the composition time stamp (Composition TimeStamp, CTS) to precisely define each The composition time point of the composition unit (Composition Unit, CU).

Use the Object Clock Reference (OCR) to send the timestamp of a given stream to the ES decoder. Whenever the sending terminal generates an OCR timestamp, the OCR value corresponds to the Object Time Base (OTB) value. The OCR value is included in the SL packet header and sent.

Korean terrestrial DMB uses both MPEG-4 and MPEG-2. In order to transmit and synchronize AV data, the MPEG-2 system uses a program clock reference (Program Clock Reference, PCR) and a presentation time stamp (PTS), while the MPEG-4 system uses a target clock reference, a synthesis time stamp and a decoding time stamp. Also, the MPEG-4 system and the MPEG-2 system are synchronized by mapping SL packets of MPEG-4 to packetized primary streams (PES) of MPEG-2 at a ratio of 1:1. Only when the SL packet header of MPEG-4 includes OCR, the PES header includes the PTS of MPEG-2. Otherwise, the PTS of MPEG-2 is not used. Furthermore, the target time base defining the timestamps for the MPEG-4 data stream is used with the MPEG-2 system clock.

Meanwhile, when the data encoder 140 of FIG. 1 encodes data based on the Multimedia Object protocol (Multimedia Objectprotocol, MOT), it transmits timing information with reference to the UTC absolute time information transmitted on the FIC channel, said MOT being data based on the DMB system specification Transport specification (i.e. Eureka-147). In short, the data encoder 140 objects data on a file or directory basis, and then groups the objects. Here, a timestamp is added to the header of the data object in UTC, which is timing information about the time when one data object is decoded and presented. However, this method has a problem that it is difficult to accurately synchronize the data with the DMB AV stream.

Contents of the invention

It is therefore an object of the present invention to provide a method and apparatus for synchronizing data with audio/video data in digital multimedia broadcasting by generating timing information related to the execution of specific events in an application To provide the time of the data synchronized with the DMB AV service.

According to an aspect of the present invention, there is provided a method for providing data synchronized with audio/video data in digital multimedia broadcasting, the method comprising the steps of: a) receiving an AV timestamp of the AV data; b) based on the AV Timestamp calculates the Timestamp of said data, said Timestamp is information about the point in time at which said data is presented at the user terminal, hereinafter, it will be simply referred to as Data Timestamp; c) generates a time stamp containing the calculated synchronization metadata of data timestamps; and d) encoding said synchronization metadata, and transmitting the encoded synchronization metadata.

According to another aspect of the present invention, there is provided a method for providing data synchronized with AV data in a DMB, said method comprising the steps of: a) dividing a received signal into AV streams and data packets; An AV stream decoder of the AV stream receives system reference time information; c) acquires a data time stamp from synchronization metadata included in the data packet; and d) compares the data time stamp with the system reference time comparing, and at the point in time at which the data timestamp coincides with the system reference time, decoding and presenting the data object file.

The present invention can synchronize data sent based on Eureka-147 with video based on MPEG-4 and MPEG-2. Thus, the present invention can contribute to the expansion of various digital multimedia broadcasting services.

Description of drawings

The above and other objects and features of the present invention will become apparent from the following description of embodiments in conjunction with the accompanying drawings, wherein:

Fig. 1 is a typical block diagram showing a conventional terrestrial digital multimedia broadcasting transmission system;

2 is a block diagram illustrating a terrestrial DMB transmission system for synchronizing data and video data in real time according to one embodiment of the present invention;

3 is a diagram describing a method of calculating a point in time of presentation data based on a composite timestamp value;

FIG. 4 is a diagram showing the structure of a data carousel shown in FIG. 3;

FIG. 5 is a diagram showing the structure of synchronization metadata shown in FIG. 3;

6 is a block diagram illustrating a terrestrial DMB transmission system for synchronizing data and video data in real time according to another embodiment of the present invention;

7 is a block diagram illustrating a terrestrial DMB transmission system for synchronizing data and video data in real time according to yet another embodiment of the present invention;

8 is a block diagram illustrating a terrestrial DMB transmission system for synchronizing data and video data in real time according to another embodiment of the present invention; and

FIG. 9 is a block diagram illustrating a receiving system capable of providing data synchronized with video data according to one embodiment of the present invention.

Detailed ways

Other objects and aspects of the present invention will become apparent from the following description of the embodiments with reference to the accompanying drawings provided later. Those skilled in the art can easily realize the technical concept of the present invention. When it is determined that detailed descriptions of related art may obscure the point of view of the present invention, such descriptions will not be provided here. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a block diagram illustrating a terrestrial DMB transmission system for synchronizing data and video data in real time according to an embodiment of the present invention.

Described terrestrial DMB transmission system comprises: audio/video signal source 200, is used for producing AV content; Digital Multimedia Broadcasting (DMB) AV coder 210, is used to encode the AV content produced into AV flow based on terrestrial DMB standard; Server 230 is used to provide multiple data services; total multiplexer 240 is used to multiplex the generated AV streams and data packets into an ensemble; DMB transmitter 250 is used to perform OFDM (OFDM) encoding and radio frequency (RF) transmission; and a network time protocol (NTP) server 220 for synchronizing the above constituent units in time. The data server 230 includes: a data signal source 231; a data management and control unit 233 for managing and controlling the data signal source and a data encoder 235; and the data encoder 235 for based on various DMB data Send and receive standards encode the resulting data.

In the DMB system, when the AV signal source 200 generates AV data in real time or fetches them from a storage device to provide moving image services, the DMB AV encoder 210 generates the AV data according to the terrestrial DMB video standard based on MPEG-4 and MPEG-2. The AV data is encoded. Here, for synchronization, the DMB AV encoder 210 inserts a target clock reference and a composite time stamp at the MPEG-4 layer, and inserts a program clock reference (PCR) and a program time stamp (PTS) at the MPEG-2 layer. The DMB AV encoder 210 provides the composite time stamp of the initial time period of the program to the data server 230.

In order to provide additional data based on Eureka-147, the data signal source 231 generates and stores various detailed data by collecting and editing JAVA-based application data, texts, images, moving pictures, etc. related to the application data. Additional data is encoded in the data encoder 235 and transmitted under the control and management of the data management and control unit 233 . Also, the NTP server 220 synchronizes the AV signal source 200, the encoder 210, and the data server 230 in time.

The data management and control unit 233 manages the point of time at which data from the data signal source 231 is inserted. It also calculates the time point at which the data is presented in the user terminal as a video time stamp based on the initial CTS of the program input from the DMB AV encoder 210, and known scene information and data addition time from the AV signal source 200. The value of (that is, the value based on CTS). The calculated synchronization information is directly sent to the data encoder 235, or is sent to the data encoder 235 as metadata for synchronization between video and data.

3 depicts a diagram of a method of calculating a point in time at which data is presented based on a timestamp value (eg, a composite timestamp value).

In the case of a recorded program, time information (V(b)) of a scene in which data synchronized with video data is to be added can be accurately extracted in advance. When video data is encoded in the DMB AV encoder 210, a time stamp such as CTS, which is the recovery time of each scene on the user terminal, is added to the header of the SL packet. In a non-streaming data broadcasting system, data files are broadcast in a data carousel before the resume time in the user terminal. Then, the user terminal downloads the data carousel, and performs data restoration at a predetermined point in time. Here, the data are downloadable applications and/or their associated data. The data may be pre-stored in a non-volatile memory.

In this specification, the data management and control unit 233 generates synchronization metadata for presented data synchronized with a specific scene, and transmits the generated synchronization metadata based on an appropriate data protocol.

FIG. 4 is a view showing the structure of the data carousel shown in FIG. 3 , and FIG. 5 is a view showing the structure of the synchronization metadata shown in FIG. 3 .

As illustrated in Fig. 5, the synchronization metadata may consist of an identifier, a trigger time, which is a video timestamp such as CTS, a related data indicator, and data. The identifier identifies the data, and the trigger time includes data decoding time, data recovery time, data erasure time in the user terminal, and it can be calculated in advance based on the time stamp of the video, which will be called Video timestamp, such as CTS. The associated data indicator indicates data that is synchronized with a specific scene and presented in conjunction with an application program executed in the user terminal. The data includes information that is needed immediately.

The synchronization metadata is added before a certain video recovery time (V(b)). Thus, the trigger time (Ts(b)) constituting the synchronization metadata should be estimated before the video restoration time (V(b)). According to the known video recovery time (V(b)) and the video time stamp information of the initial time period of the application, the time for calculating the trigger time Ts(b) can be obtained. The video time stamp information includes video information and time stamp information and Input from DMB AV encoder 210. Here, in all devices, the video time stamp information of the initial period of the program is time-synchronized with the NTP server, and the video time stamp information can be easily extracted.

In the case of simple synchronization metadata providing services, as shown in Figure 4, the video timestamp information is directly added to the header of the data object repeatedly sent by the data carousel without using synchronization metadata, thereby synchronizing the data The recovery time and video of the object.

Hereinafter, synchronization metadata will be described in detail with reference to examples.

In order to provide DMB service and synchronized data service, a trigger time synchronized with the video and indicating the execution of a specific event in the application should be generated, and the generated trigger time should be sent from the data server of the sender to the Ground DMB middleware. In other words, when the user terminal executes the application, the sender should send the trigger time and the data to be executed or an indicator of the data to execute an event synchronized with the video. A message consisting of a trigger time and data to be executed or an indicator of data is called a trigger packet. In short, the trigger packet is an example of the synchronization metadata.

The trigger packet should be scheduled and sent from the sender's data server before a predetermined synchronization trigger time to cause the application to execute the event. When the trigger time is reached, the trigger packet is repeatedly sent to cause the application to perform a predetermined action indicated by the event at a timing synchronized with the video.

Terrestrial DMB uses a transparent data channel (Transparent Data Channel, TDC) packet mode with small overhead instead of data groups with short latency. The TDC packet mode is based on ETSI TS 101 759 (i.e. Digital Video Broadcasting (DAB)); DAB Digital Broadcasting Transparent Data Channel (TDC) standard to send trigger packets. Trigger packets may be sent by using other transport protocols.

Table 1 below shows the format of the trigger packet.

Table 1

Format number of digits bit format trigger_packet(){triggerIDtriggerTimefor(i=0; i<N; i++){privateDataByte}} 16338 uimsbfuimsbfuimsbf

In Table 1, "triggerID" is an identifier identifying a trigger in an application program, and "triggerTime" indicates a time point at which an event is generated. Video time stamps such as CTS are used around the point in time when the event is generated to provide connection services. Here, the video service providing device and the data server need to cooperate to use the CTS at the trigger time.

"privateDataByte" indicates that the application needs the data required to execute the event at fire time. privateDataByte may consist of related data indicators and data, as shown in Figure 5.

API model

The terrestrial DMB middleware defines a trigger interface in the dmb.io packet defined for data reception over the DMB data channel to provide synchronized data services. The API model is extended from javax.microedition.Datagram (CLDC 1.1 (JSR139), on the web page http://java.sun.com/products/cldc/index.jsp), and it is a datagram that includes event information . Use triggers to send sync signals to other media. The API model links trigger ID and time information when an event indicated by the trigger is to be executed.

Although multiple triggers are received on the broadcast network, if these triggers have the same ID, they are treated as the same trigger. A flip-flop may be sent several times to increase the probability of reception or to confirm the time indicated by the flip-flop since the time may be changed due to discontinuities in the system clock. When the time indicated by the trigger has elapsed, the trigger will be ignored. The ID of a trigger whose time has elapsed and whose processing is complete can be reused by other triggers.

When even one trigger with the same ID is received, the trigger object is received immediately. When the time indicated by the trigger has not arrived, doItNow() is False. A trigger with fake doItNow() is sent to the application only once, even if a trigger with the same ID is sent several times. Even, the trigger with the same ID can be sent several times when the trigger time is changed in between. When the trigger time is approaching or slightly past at the time the event is generated, a trigger whose doItNow() is true is sent to the application. The application immediately performs the action indicated by the trigger. After execution, even if a trigger with the same ID is sent, the trigger is considered different than the trigger for which doItNow() is true.

The privateData sent in the form of a trigger packet is read by using a method of a Diagram, which is an upper class of the trigger.

Table 2 below defines the API for the synchronization service.

Table 2

public interface dmb.io.Trigger All extended Interfaces javax.microedition.io.Datagram Methods public long doItNow() false, if the trigger informs prior to an event generation time, or true, if operation should be executed as soon as an event is received. public long getID() returns ID of the trigger public long getTime() returns time information indicated by the trigger.

FIG. 6 is a block diagram illustrating a terrestrial DMB transmission system for synchronizing data and video data in real time according to another embodiment of the present invention. The drawing shows an example of the system, wherein, when the DMBAV encoder 410 cannot directly output the time information of the video source and its timestamp information to the data server 430, the data server 430 uses the timestamp extraction unit 437. The time stamp extraction unit 437 extracts a video time stamp (for example, video CTS) from the AV stream output from the DMB AV encoder 410, and the extracted time stamp is input to the data management and control unit 433.

In this case, in order to calculate the timestamp (Ts(b)) of the data constituting the synchronization metadata in advance, the encoding delay time of the DMB AV encoder 410, which can be obtained in advance from experiments, should be additionally considered.

When AV data is encoded in advance and stored in the form of a stream, synchronization data can be provided more easily, which is shown in FIGS. 7 and 8 . In this case, the time of the video to which the data will be added and its timestamp can be obtained in advance.

7 is a block diagram illustrating a terrestrial DMB transmission system for synchronizing data and video data in real time according to still another embodiment of the present invention.

In the drawing, an AV stream is stored in an MPEG-2 file or a forward error correction (FEC)-added file thereof.

Referring to FIG. 7, the DMB transmission system includes an AV signal source 500, an AV encoder 510 for encoding an AV signal based on the terrestrial DMB standard, a storage device 560 for storing the encoded AV signal in the form of a stream, and by using the AV signal provided from the storage device 560. The time stamp generates synchronization metadata to provide data server 530 synchronized with AV data, and multiplexers 520, 540, and 550 for multiplexing the output signal of the AV encoder 510 and the output signal of the data server 530. Here, video time information of a video to which data is to be added and a data time stamp for data restoration are input to the data server 530 in advance. The data management and control unit 533 determines when to add data and generates synchronization metadata based on the time when data is added.

In the normal DMB service shown in FIG. 7, when data is provided during the transmission of the AV stream from the DMB AV encoder 510, stream conversion occurs in the converter. Converter 520 performs re-stamping, which is the process of ensuring timestamp continuity. In the converter 520, the time stamp previously added to the stream file is re-established to be continuous with the time stamp of the AV stream output from the DMB AV encoder 510. In summary, a predetermined value is added to the timestamp. The data server 530 should receive the time stamp of the AV stream reconstructed in the converter 520 and information on the time point at which conversion has occurred in order to reflect the reconstruction. The time stamp reconstruction is to shift the entire time stamp by a predetermined value. As such, information needs to be entered at the moment the transition occurs.

FIG. 8 is a block diagram illustrating a terrestrial DMB transmission system for synchronizing data and video data in real time according to another embodiment of the present invention.

Different from the transmission system in FIG. 7, in the transmission system in FIG. 8, the AV stream is encoded in the form of an MP4 file, and is directly added to the DMB AV encoder 610.

When the AV stream is encoded into the MPEG-4 format and is added to the DMB as an MP4 file in a stored file format, the MP4 file should be grouped into MPEG-4 SL and MPEG-2 transport streams in the M4onM2 processing module 620 (TS), which is shown in FIG. 8 . This process can be performed in the DMB AV encoder 610, but can also be performed in an additional device.

When MP4 files are grouped into MPEG-4 SL and MPEG-2 TS, the comparison time information in MP4 files is converted into OCR or CTS. The data server 630 already contains the time information of the video to which the data will be added and the data timestamp for data recovery. This way, if it receives transformation information from an MP4 file to a packet operation of MPEG-4 SL and MPEG-2 TS, it can predict the data timestamp, which is the time at which the data synchronized with the video is presented.

FIG. 9 is a block diagram illustrating a receiving system capable of providing a service in which data and video are synchronized according to one embodiment of the present invention.

Referring to FIG. 9, a receiving system capable of providing video synchronized with data includes an RF receiving channel decoder 710, an MSC processor 730, a DMB AV decoder 740, a DMB data decoder 760, and a data presentation device 770. The RF reception channel decoder 710 receives an RF signal, demodulates the RF signal into a baseband signal, performs channel decoding, and separates FIC data from MSC data. The FIC analyzer 720 analyzes FIC data including multiplex information and service information, and provides the analysis result to the MSC processor 730 . The MSC processor 730 separates data transmitted through the MSC channel into data packets and AV streams. The AV stream and the data packets are respectively input to the DMB AV decoder 740 and the DMB data decoder 760 for decoding. The DMB AV presentation means 750 and the data presentation means 770 respectively present the AV stream and the data at the same restoration time.

The DMB data decoder 760 receives system reference time information such as OCR from the DMB AV decoder 740, and compares the system reference time information with the CTS-based data timestamp. Here, the coincident time becomes the restoration time of the data object file. Finally, the data presentation means 770 executes the application program indicated by the synchronization metadata, and at the extracted restoration time, presents the relevant data indicated by the synchronization metadata and the instant data added to the synchronization metadata to be synchronized with the AV data, respectively.

The method of the present invention described above can be realized as a program and stored in a computer-readable recording medium such as CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, and the like. Since this process can be easily implemented by those skilled in the art, a detailed description about it will not be provided here.

Although the invention has been described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims. Revise.

Claims (23)

1. one kind is used for providing method with the data of audio/video (AV) data sync at DMB (DMB), comprises step:

A) the AV timestamp of reception AV data;

B) calculate the timestamp of described data based on described AV timestamp, the timestamp of described data is about presenting the information of the time point of described data at user terminal, and it will be called data time in the back for short and stab;

C) produce the synchronizing metadata that comprises the data time stamp that is calculated; And

D) the described synchronizing metadata of encoding, and send encoded synchronizing metadata.

2. extract described AV timestamp in the AV stream that the method for claim 1, wherein from encoded, obtains.

3. the method for claim 1, wherein the AV stream file from storage provides described AV timestamp.

4. the method for claim 1, wherein described synchronizing metadata is to trigger grouping, and it comprises the information that is used to carry out with the incident of described AV data sync.

5. method as claimed in claim 4, wherein, described triggering grouping comprise the trigger of the application program that is used for being identified at the recipient field, be used to indicate the field and being used to of the time point of generation incident to indicate the field of the data that described application program carries out at the triggered time point.

6. method as claimed in claim 5, wherein, described triggering is repeated to send before being grouped in described triggered time point.

7. one kind is used for providing method with the data of audio/video (AV) data sync at DMB (DMB), comprises step:

A) received signal is divided into AV stream and packet;

B) from the AV stream decoder receiving system reference time information of the described AV stream that is used to decode;

C) synchronizing metadata from be included in described packet obtains the data time stamp;

D) more described data time stabs and the described system reference time, and at the described data time stamp time point consistent with the described system reference time, decodes and presents data object file.

8. method as claimed in claim 7, wherein, described synchronizing metadata is to trigger grouping, it comprises the information that is used to carry out with the incident of described AV data sync.

9. method as claimed in claim 7, wherein, described synchronizing metadata is to trigger grouping, it comprises the information that is used to carry out with the incident of described AV data sync.

10. method as claimed in claim 9, wherein, described triggering grouping comprise the trigger of the application program that is used for being identified at the recipient field, be used to indicate the field and being used to of the time point of generation incident to indicate the field of the data that described application program carries out at described triggered time point.

11. method as claimed in claim 9, wherein, if described triggering grouping was used for before scheduled event produces, the generation of this incident of prior notice, then the application program to the recipient sends glitch, perhaps, if described triggering grouping is used to respond the generation of described incident and instant deal with data, then the application program to the recipient sends true signal.

12. one kind is used for providing device with the data of audio/video (AV) data sync at DMB (DMB), comprises:

The AV encoder is used for being provided to data server based on terrestrial DMB standard code AV signal and with the AV timestamp;

The data synchronization metadata that provides with the AV data sync by using described AV timestamp to produce to be used to is provided data server;

The time synchronized server is used for synchronous in time described AV encoder and described data server; And

Multiplexer is used for the output signal of multiplexing described AV encoder and the output signal of described data server, and sends through multiplexing signal.

13. device as claimed in claim 12, wherein, described data server comprises:

Data signal source is used to produce the several data relevant with described DMB;

Data management and control unit are used for coming the calculated data timestamp based on described AV timestamp, and it is the time point that presents described data at user terminal that described data time stabs, and produce the synchronizing metadata that comprises the data time stamp that is calculated; And

Data encoder is used for described several data and described synchronizing metadata are encoded to packet.

14. device as claimed in claim 12, wherein, described synchronizing metadata is to trigger grouping, and it comprises the information that is used to carry out with the incident of described AV data sync.

15. device as claimed in claim 14, wherein, described triggering grouping comprise the trigger of the application program that is used for being identified at the recipient field, be used to indicate the field and being used to of the time point of generation incident to indicate the field of the data that described application program carries out at described triggered time point.

16. device as claimed in claim 14, wherein, described triggering is repeated to send before being grouped in described triggered time point.

17. one kind is used for providing device with the data of audio/video (AV) data sync at DMB (DMB), comprises:

The AV encoder is used for the signal based on terrestrial DMB standard code AV;

Memory is used for the encoded AV signal of form storage with stream;

The AV timestamp that provides from described memory by using is provided data server, and the data synchronization metadata that is used to provide with the AV data sync is provided; And

Multiplexer is used for the output signal of multiplexing described AV encoder and the output signal of described data server, and sends through multiplexing signal.

18. device as claimed in claim 17, wherein, described synchronizing metadata is to trigger grouping, and it comprises the information that is used to carry out with the incident of described AV data sync.

19. device as claimed in claim 18, wherein, described triggering grouping comprise the trigger of the application program that is used for being identified at the recipient field, be used to indicate the field and being used to of the time point of generation incident to indicate the field of the data that described application program carries out at described triggered time point.

20. one kind is used for providing device with the data of audio/video (AV) data sync at DMB (DMB), comprises:

RF receive channel decoder is used to receive the DMB signal, and described DMB signal is demodulated to baseband signal, and carries out channel-decoding;

The MSC processor is used for based on multiplexed information and information on services, isolates AV stream from packet;

The AV stream decoder, described AV stream is used to decode; And

Data present device, are used for being included in the synchronizing metadata of described packet and from the system reference time that the AV stream decoder provides by use, provide and described AV stream data in synchronization.

21. device as claimed in claim 20, wherein, described synchronizing metadata is to trigger grouping, and it comprises the information that is used to carry out with the incident of described AV data sync.

22. device as claimed in claim 21, wherein, described triggering grouping comprise the trigger of the application program that is used for being identified at the recipient field, be used to indicate the field and being used to of the time point of generation incident to indicate the field of the data that described application program carries out at described triggered time point.

23. device as claimed in claim 21, wherein, if described triggering grouping was used for before scheduled event produces, the generation of this incident of prior notice, then the application program to the recipient sends glitch, perhaps, if described triggering grouping is used to respond the generation of described incident and instant deal with data, then the application program to the recipient sends true signal.

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